Fig 7.

NK cells from Gal-9 KO mice respond to stimulation with enhanced cytokine production and degranulation. For the induction of IFN-γ, splenic cells were stimulated with cytokines IL-12 (1 ng/ml) and IL-18 (10 ng/ml) for 6 h in the presence of brefeldin A (BFA). After culture, cells were washed and stained for cell surface expression of CD3 and NK1.1 to identify NK cells. After fixation and permeabilization, intracellular staining for IFN-γ was performed. (A) Cytokine stimulation results in greater production of IFN-γ by NK cells from Gal-9 KO mice (n = 5 in each group). (B) Degranulation (CD107a expression) was measured after 6 h of stimulation with PMA and ionomycin in the presence of BFA. NK cells from KO mice demonstrated enhance degranulation compared to wild-type (WT) mice. The bars show means ± SEM, and Student's t test was used to test statistical significance. Representative flow-cytometric histograms are shown for cytokine-stimulated intracellular IFN-γ production and PMA-ionomycin-stimulated CD107a expression in WT and KO mice. The percentages represent the proportion of total NK cells positive in each subset.